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Author Topic: Threading up Simplex 35s - Proper Frameline Position on Holdback Sprocket Matt Hollis Film Handler Posts: 49 From: Paragould / Jonesboro, AR, USA Registered: Jan 2005 posted 10-31-2007 05:06 PM                        Tonight at work I think I'm gonna give it a shot "threading up" by Simplex 35s. What is the correct frameline position on the holdback sprocket to ensure my movies are in frame. I have 5 Stars by the way, and this assumes I thread by the book by pulling the arm all the way to the stop and backing it off one perf. I also feel the best way to deal with the platters is to bypass the platter's take-up arm until I'm finished threading the machine. If anyone has a better suggestion on how to do that please mention it. (Potts A-3s by the way)  |  IP: Logged Mike Blakesley Film God Posts: 12767 From: Forsyth, Montana Registered: Jun 99 posted 10-31-2007 05:49 PM                        Your post is confusing. At first it sounds like you're talking about threading in frame, but by the end it sounds like you're talking about having the sound in sync with the picture. Which is it? Don't you have a framing light? If you can see the frame lines in the lit "box" then you're out of frame. I'm not sure what you mean by holdback sprocket...the intermittent sprocket?  |  IP: Logged Robert E. Allen Phenomenal Film Handler Posts: 1078 From: Checotah, Oklahoma Registered: Jul 2002 posted 10-31-2007 06:42 PM                     All projectors have a "framing port" with a light behind it which is used for properly framing the picture. The hold-back sprocket (which is at the bottom of your sound head) has nothing to do with framing.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 10-31-2007 06:46 PM                     Yea, you pull that lower snub roller tight while pulling on the film across that lower holdback sprocket, then back it off one sprockethole then close the pad roller assembly over the sprocket on the 5-Star soundhead unit. You turn the motor flywheel, watch the intermittent sprocket to make a quarter turn, then when the sprocket stops, you stop turning the flywheel and frame the film to the framebox accordingly before closing the gate and trap assembly.  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 10-31-2007 07:07 PM                     I could be completely wrong here, but I think what Matt is talking about here is threading the projector from the bottom up, the way Brad describes in this tip. Literally, "threading up." Since the holdback sprocket -- and not the framing aperture -- is the first thing you will thread after you pull the film up out of the failsafe, he wants to know where the frameline should land so that the film in the gate will be in frame. Off the top of my head, I don't know. You will have to experiment a little to see what works best.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 10-31-2007 07:24 PM                     Thread it with perfect loops and in frame any way you want to achieve that goal. THEN once you have a piece of film in the projector threaded exactly as you want it, advance the motor until the pulldown just stops and take a look at the holdback sprocket. There lies your answer.  |  IP: Logged Ron Curran Jedi Master Film Handler Posts: 504 From: Springwood NSW Australia Registered: Feb 2006 posted 10-31-2007 08:25 PM                        Brad, I'm terrified to add this, but we hand advance, not motor advance.  |  IP: Logged Mike Blakesley Film God Posts: 12767 From: Forsyth, Montana Registered: Jun 99 posted 10-31-2007 08:31 PM                        I think Brad meant to hand-advance, because he said "until it just stops." But Brad's suggestion will only work if the projectionist can remember EXACTLY the size of the loops every time. Bottom line, you need to use the framing light or the lightbox or whatever it's called in your part of the world. I never heard that soundhead sprocket referred to as the holdback sprocket until today. To me it's always just been the soundhead sprocket. Learning something new every day is good.  |  IP: Logged Blaine Young Master Film Handler Posts: 477 From: Kirkland, WA, USA Registered: Sep 2006 posted 10-31-2007 08:59 PM                     I've always threaded everything from the top down - until I started working on the Apogee heads from Strong. The thread on these is just so stupid, I can't make my fingers do all the right things to thread the gate correctly. So I thread from the 'idle' sprocket down through the sound head and then go back and thread the intermittent and gate, and finally the top sprocket. These heads are the dumbest design I've ever seen.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 10-31-2007 09:50 PM                     quote: Mike Blakesley I never heard that soundhead sprocket referred to as the holdback sprocket until today.. That term comes from the lower sprocket in the 4-star (SH-1000) soundhead being the "holdback" sprocket-holding back the film before entering into the takeup magazine. The upper sprocket is called the "sound" sprocket. Yet, I've always called them, "the upper and lower" holdback sprockets. quote: Blaine Young These heads are the dumbest design I've ever seen. Why Christie is the better projector. (whoops, did I say that too loud??)  |  IP: Logged Matt Hollis Film Handler Posts: 49 From: Paragould / Jonesboro, AR, USA Registered: Jan 2005 posted 11-01-2007 04:45 PM                        Yeah, Ken hit the nail on the head. I guess I wasn't specific enough. I guess I'll just take a scrap loop and thread it like Brad said. I just didn't know if anyone had a quick answer since I was short on time.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 11-01-2007 10:18 PM                     True Matt, if you try this on those Apogees, in as much where I can do that reverse threading on my older Simplexes, it really does work the first time. Thing is - you're going to have to think backwards for a while to get the hang of it. But after you do, then it'll come naturally.  |  IP: Logged Scott McGuire Film Handler Posts: 94 From: Elmira, NY/United States Registered: Oct 2007 posted 11-02-2007 01:49 AM                     We have Simplex XL projectors and learned from that start from our tech guy to "thread-up" or backwards. He never mentioned anything about the framing port to us during training, but my father who was a projectionist for 25ish years pointed it out to me one day while he was checking out the booth. What i do is thread all the way making sure i am in frame when i close the gate and then adjust my second loop to the proper size after that i adjust the film on the holdback sprocket.  |  IP: Logged Michael Cunningham Expert Film Handler Posts: 186 From: Anchorage, AK Registered: Nov 1999 posted 11-02-2007 02:34 AM                     As to the term Holdback Sprocket, if I'm not mis-remembering, I think I've seen the lower feed sprocket (last sprocket in the actual projector mechinism) listed as such in older manuals. Perhaps this is a hold-over from the pre-sound days when this would have been the sprocket "holding back" against the take-up reel?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 11-02-2007 01:04 PM                     The term "Holdback" sprocket came out with the SH-1000 and with the RCA's version of the same head. For the projector, that lower sprocket was called thus: "lower sprocket". That sprocket also "held back" the film to keep that loop created inbetween the upper sound sprocket and the holdback sprocket for these heads in check during operation. For the "5-Star" heads, that lower sprocket was never given this name, offically, as a holdback sprocket. It's just simply called a "sprocket". Just that some of us still call that sprocket by this "Holdback" name since it's basically doing the same job as the sprocket in those "4-Star" (SH-1000) soundheads-"holding" back the film inbetween the lower sprocket of the projector and that sprocket since the snubber roller is doing what the sound sprocket did in that older head. that "4-star" head design was the "gem" of the industry in the way it handled the film and with that fluid filled flywheel for the inpedence drum, really kept wow and flutter down to a minimum..  |  IP: Logged

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